package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.Collections;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Autowired
    private ISeckillVoucherService seckillVoucherService;
    @Autowired
    private RedisIdWorker redisIdWorker;
    @Autowired
    private StringRedisTemplate stringRedisTemplate;
    @Autowired
    private RedissonClient redissonClient;

    // 代理对象(注入自己)
    @Autowired
    private VoucherOrderServiceImpl proxy1;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;

    IVoucherOrderService proxy;

    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
    // 阻塞队列
    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
    // 线程池
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();


    public VoucherOrderServiceImpl() {
        SECKILL_ORDER_EXECUTOR.submit(new Runnable() {
            @Override
            public void run() {
                while (true) {
                    try {
                        // 1.获取队列中的订单信息
                        VoucherOrder voucherOrder = orderTasks.take();
                        // 2.创建订单
                        handleVoucherOrder(voucherOrder);
                    } catch (Exception e) {
                        log.error("处理订单异常", e);
                    }
                }
            }
        });
    }

    /**
     * 处理订单
     * @param voucherOrder
     */
    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        //创建redisson锁对象
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        //获取锁
        boolean isLock = lock.tryLock();
        if (!isLock) {
            // 获取锁失败, 返回错误或重试
            log.error("不允许重复下单");
            return;
        }
        try {
            // 获取代理对象
            //IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            proxy.createVoucherOrder(voucherOrder);
        } catch (IllegalStateException e) {
            throw new RuntimeException(e);
        } finally {
            // 释放锁
            lock.unlock();
        }
    }

    /**
     * 秒杀优惠券
     * @param voucherId
     * @return
     */
    @Override
    public Result seckillVoucher(Long voucherId) {
        Long userId = UserHolder.getUser().getId();
        //1.执行lua脚本
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString());

        int r = result.intValue();
        if (r != 0) {
            switch (r) {
                case 1:
                    return Result.fail("库存不足");
                case 2:
                    return Result.fail("不能重复下单");
            }
        }
        //为0,可以购买
        //获取订单id
        Long orderId = redisIdWorker.nextId("order");
        // 5.创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        // 5.1.订单id
        long nextedId = redisIdWorker.nextId("order");
        voucherOrder.setId(nextedId);
        // 用户id
        voucherOrder.setUserId(userId);
        // 优惠券id
        voucherOrder.setVoucherId(voucherId);
        //放入阻塞队列
        orderTasks.add(voucherOrder);
        //获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();

        return Result.ok(orderId);
    }
    /*@Override
    public Result seckillVoucher(Long voucherId) {
        // 1. 查询优惠券
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        // 2.判断开始结束
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())
                || voucher.getEndTime().isBefore(LocalDateTime.now())) {
            return Result.fail("秒杀尚未开始或已经结束");
        }
        // 3.判断库存
        if (voucher.getStock() < 1) {
            return Result.fail("库存不足");
        }

        Long userId = UserHolder.getUser().getId();
        //创建redisson锁对象
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        //SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
        boolean isLock = lock.tryLock();
        if (!isLock) {
            // 获取锁失败, 返回错误或重试
            return Result.fail("不允许重复下单");
        }
        //先获取锁, 保证线程安全
        *//*synchronized (userId.toString().intern()) {
        }*//*
        try {
            // 获取代理对象
            IVoucherOrderService proxy  = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        } catch (IllegalStateException e) {
            throw new RuntimeException(e);
        } finally {
            // 释放锁
            lock.unlock();
        }
    }*/

    /**
     * 创建订单(异步处理)
     *
     * @param voucherOrder
     */
    /*@Transactional
    public Result createVoucherOrder(Long voucherOrder1) {
        // 判断是否重复抢购
        Long userId = UserHolder.getUser().getId();
        Integer count = query().eq("user_id", userId).eq("voucher_id", voucherOrder1).count();
        if (count > 0) {
            return Result.fail("不能重复下单");
        }
        // 4.扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherOrder1)
                .gt("stock", 0)
                .update();
        if (!success) {
            return Result.fail("库存不足");
        }
        // 5.创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        // 5.1.订单id
        long nextedId = redisIdWorker.nextId("order");
        voucherOrder.setId(nextedId);
        //用户id
        voucherOrder.setUserId(userId);
        // 优惠券id
        voucherOrder.setVoucherId(voucherOrder1);
        save(voucherOrder);
        return Result.ok(nextedId);
    }*/
    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        // 判断是否重复抢购
        Long userId = voucherOrder.getUserId();
        Integer count = query().eq("user_id", userId).eq("voucher_id", voucherOrder).count();
        if (count > 0) {
            log.error("不能重复下单");
        }
        // 4.扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherOrder.getVoucherId())
                .gt("stock", 0)
                .update();
        if (!success) {
            log.error("库存不足");
        }
        // 5.创建订单
        save(voucherOrder);
    }
}
